Flood Study Projects

  • Paterson River Flood Study: In April 2015 the Paterson and Williams Rivers both experienced major flooding, with devastating consequences throughout the valley. Three people were killed in flash flooding and at Dungog there was significant damage to houses, with some properties being washed off their footings. The flood appears to be the highest at the Gostwyck Bridge gauge since detailed records were established in 1928.
  • Greater Macquarie Rivulet Catchment Flood Study: WMAwater have been engaged by Shellharbour City Council to undertake a Flood Study for the Great Macquarie Rivulet catchment. As urbanisation and development continues, the ability to effectively manage flood prone lands will be dependent on an accurate assessment of existing flood conditions upon which to base future floodplain management decisions. It is therefore important that appropriate tools and information to assess flood risk are available to Shellharbour City Council for planning purposes.
  • Medowie Flood and Drainage Study: The Medowie area, located five kilometres to the north-east of Raymond Terrace in NSW, has in recent years undergone considerable residential development and potentially more may occur in the future. Rural and rural residential lots are being sub-divided for suburban lots and in some locations new development is proposed. A challenge that faces planners is that within both the Campvale and Moffats Swamp catchments which comprise Medowie, some areas are subject to inundation by flooding in relatively small flood events (1Y to 5Y ARI). A further complication is that the Campvale catchment is a drinking water supply catchment and so drainage solutions must take account of water quality impacts.
  • Wollongong Flood Study: The key objective of the Flood Study was to develop a suitable hydraulic model that can be used as the basis for a Floodplain Risk Management Plan for the study area, which will assist Wollongong City Council to undertake flood-related planning decisions for existing and future developments. Previous hydraulic modelling of the study area was limited in extent, and did not estimate flood levels or flows in residential areas of the catchment.
  • Warragamba Dam and Hawkesbury Nepean:The NSW government wishes to investigate flood behaviour in the Hawkesbury Nepean and mitigation options to reduce flood risk to large downstream population centres in Sydney.

Infrastructure Projects

  • Nundah Creek SOBEK Model Conversion: Conversion of the Nundah Creek SOBEK model to a nested model with 2m grid areas embedded within a 6m parent model. This converted model forms the basis of the Gateway Upgrade North flood model.
  • Warrell Creek to Urunga: The proposed upgrade of the Pacific Highway between Warrell Creek and Urunga is part of the Pacific Highway upgrade program being implemented by Roads and Maritime Services (RMS) . The project is 42 kilometres in length, commencing at the northern end of the existing dual carriageway highway at Allgomera (referred to as the Allgomera deviation), connecting with the existing Waterfall Way interchange, north of Urunga.
  • Kempsy Bypass: The Kempsey Bypass is the initial stage of the Kempsey to Eungai Upgrade project, involving a 14.5km four-lane divided highway which crosses the Macleay River floodplain to the east of Kempsey. The 3.2km bridge across the Macleay River and floodplain is the longest in Australia. WMAwater were heavily involved in all phases of the project.
  • South-West Rail Link: The South West Rail Link (SWRL) has been proposed by the NSW Government as part of a commitment to infrastructure for the South West Growth Centre urban release areas. The 13.2 km line will provide a link from the existing Glenfield station to the urban release areas of Edmondson Park and Leppington. The proposed alignment crosses a number of waterways including the Bunbury Curran floodplain, and the upper tributaries of Cabramatta and Maxwells Creek.
  • Independent Hydrological Advice to Road Projects: The NSW Roads and Maritime Services (RMS) is currently upgrading large sections of highway and motorways within NSW. These major roads are vital to connect our communities but also for the transport of produce and safe egress from flood waters. In flood emergencies these routes can be cut off leaving communities isolated from vital services.

Urban Drainage Projects

  • Marrickville Flood Study: A Flood Study constitutes the first stage of the NSW floodplain risk management process. WMAwater completed a Flood Study for the areas including and adjacent to Marrickville (including parts of or all of the suburbs of Petersham, Stanmore, Enmore, Newtown, St Peters, Tempe, Marrickville and Dulwich Hill). The study was prepared for Marrickville Council under the guidance of NSW Government staff and Council’s Floodplain Risk Management Committee (FMC). The study involves the development of models and the quantification of the existing flood risk, and provides the basis for the future management of flood liable lands within the study area.
  • Perth Airport Master Drainage Strategy: Perth Airport covers an area of approximately 2,100 hectares and since 1997 has been operated by Perth Airports Pty Ltd, who are undertaking substantial redevelopment of the airport estate. The planning framework for future development as outlined in the Perth Airport Master Plan includes an additional runway, new aprons, taxiways, terminal upgrades, improved road access, and significant commercial development outside of core airport-related activities.

Floodplain Management Projects

  • Murrumbidgee River (Hay to Maude): The Hay to Maude study area encompasses 80 km of the lower Murrumbidgee River with the entire study area covering some 1,800 km2 . WMAwater were engaged to undertake a Floodplain Risk Management Study through two Phases, A and B. Phase A of the project comprised a Flood Study and data collection, which included a desktop environmental assessment. The key objective of Phase B was to develop community owned strategies for the management of the floodplain and its resources in the form of a Floodplain Risk Management Study and Plan.
  • Victoria Park: The Victoria Park Urban Renewal area is located at the site formerly occupied by Waterloo lagoon and swamp. The swamp was drained in the early 20th century and a racecourse was built, to be replaced after World War II by the Zetland Naval Stores depot, which occupied the site until the mid 1990s. Significant redevelopment of this area in the form of medium and high density housing as well as commercial premises has occurred in recent years, presenting many challenges in floodplain management.
  • Maitland Floodplain Management: The catastrophic 1955 flood at Maitland, which caused 14 deaths in the Maitland area, was a major catalyst for the development of modern floodplain management practices in New South Wales. The Lower Hunter River Flood Mitigation Scheme involves several kilometres of levees, floodways, and flood control structures. However, Maitland is still vulnerable to large floods, and floodplain management for the city is a primary ongoing concern.

Expert Review, Advice and Testimony Projects

  • Department of Science, Information Technology and Innovation (Queensland): Providing expert advice and assistance to the Queensland Hydrology Group, including assisting the investigation into the security of urban water supplies throughout the Queensland; providing the expert assistance in the development of the water sharing rules to provide urban and rural users better ways of managing the water for their applications; and assisting in the development of new approaches in defining rural water supply reliability
  • Independent Panel of Experts – Department of State Development, Infrastructure and Planning: Member of the technical/scientific advisory panel to provide ongoing advice in regard to issues relating specifically to flooding and floodplain management of the Brisbane River and its major tributaries. WMAwater provides professional expertise and advice on scientific and technical matters related to the Brisbane River Catchment Studies.
  • Lockyer Valley Flood Study Review: WMAwater reviewed the gauging station interpretation and flood estimation for Lockyer Creek Flood Study. A review of the critical assumptions underlying the flood study was necessary particularly those to which the outputs are sensitive. It was important to also understand how these assumptions affect the uncertainty of the flood estimates. A key part of the review was assessing if the study presents a best estimate or a conservative estimate. It was necessary to confirm that the assumptions did not combine in a way that biases the flood study results.
  • Queensland Floods Commission of Inquiry: In the aftermath of the devastating floods that struck Queensland in January 2011, affecting over two-thirds of the state, a Commission of Inquiry was formed, charged with undertaking an independent and thorough examination of the chain of events leading to the floods, all aspects of the response and the subsequent aftermath of the 2010/2011 flood events. WMAwater was appointed as the technical expert advising the Commission, and submitted several reports.

Coastal and Maritime Projects

  • Deep Creek ICOLL: Deep Creek is an ICOLL on the NSW north coast which is largely open. WMA conducted a flood study and climate change assessment for Council and the RMS for Deep Creek catchment. Based on model results an entrance opening strategy was recommended.

Hydrologic Projects

  • Bellinger, Kalang and Nambucca Catchments Regional Hydrology: WMAwater conducted an investigation into the known hydrologic issues in the Bellinger, Kalang and Nambucca catchments. This area of the NSW coast has presented a range of challenges for a number of studies where problems have been encountered matching rainfall runoff modelling with flood frequency results.